Substrate and sequential site specificity of cytoplasmic histone acetyltransferases of maize and rat liver.
The cytoplasmic B-type histone acetyltransferase was purified to apparent homogeneity from maize embryos. We established a novel protocol for easy large-scale preparation of acetylated core histone species, using preparative acetic acid-urea-Triton PAGE. The pure maize histone acetyltransferase B was highly specific for histone H4 under various assay conditions, modifying H4 up to the di-acetylated isoform. Only non-acetylated H4 isoform was accepted as substrate, whereas mono-acetylated H4 could not be further acetylated. The enzyme selectively acetylated lysines 12 and 5 in a sequential manner. The same results were obtained with a partially purified cytoplasmic histone acetyltransferase of rat liver. Protein sequencing results were supported by immunological characterization of acetylated H4 subspecies with site-specific H4-acetyllysine antibodies.
Kölle
D
D
Department of Microbiology, University of Innsbruck Medical School, Austria.
Sarg
B
B
Lindner
H
H
Loidl
P
P
D000107:Acetylation; D000123:Acetyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002645:Chickens; D003593:Cytoplasm; D051548:Histone Acetyltransferases; D006657:Histones / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D051381:Rats; D029701:Saccharomyces cerevisiae Proteins; D013379:Substrate Specificity; D003313:Zea mays / Q000201:enzymology*
D006657:Histones; D029701:Saccharomyces cerevisiae Proteins; D000123:Acetyltransferases; D051548:Histone Acetyltransferases